As a method for treating coronary stenoses, a minimally invasive treatment using a catheter has become widespread. In performing this operation, infusion of a radiopaque material is carried out for checking the position of the catheter or the condition of the stenosed portion. In addition, flushing with physiological saline is appropriately conducted for securing an image contrast. Furthermore, while the circuit in the operation is constantly connected to a pressure monitor for measuring (detecting) and displaying the arterial blood pressure and the blood pressure is being checked, the connection to the pressure monitor is cut off at the time of introducing the radiopaque material or the physiological saline.
For performing each of these operations, the flow passage in the circuit has to be changed over. As means for changing over the flow passage, conventionally, a triplet of three-way cocks has been used.
In the case of the triplet of three-way cocks, however, there are three cocks and it is necessary to operate the three cocks. Therefore, the operation required is intricate, and thus it has been impossible to change over the flow passage swiftly.
In addition, for facilitating these operations, the device described in Patent Document 1, for example, has been known. In the device, however, changeover between a radiopaque material route (flow passage) and a pressure monitor route can only be performed, and changeover to a physiological saline route cannot be achieved. Further, an addition of a physiological saline route is difficult to realize, since such an addition leads to a complicated mechanism.
Patent Document 1:
Japanese Laid-Open Patent Publication No. 09-108360